Theseus Pharmaceuticals disclosed in a US securities filing on Monday that it will review and evaluate an expression of interest from Foresite Capital and OrbiMed Advisors, as well as a proposal from Concentra Biosciences. The news follows a recent decision by Theseus to lay off 72% of its workforce, months after its experimental treatment THE-630 was derailed in a Phase I/II trial of patients with gastrointestinal stromal tumours.According to the securities filing, Theseus' board received an unsolicited joint letter on November 22 from Foresite and OrbiMed indicating their intent to explore a possible acquisition of all Theseus shares they do not already own. Such a transaction would take Theseus private again. The company had raised $160 million in an upsized initial public offering back in 2021.Meanwhile, Theseus also disclosed that its board also received an unsolicited proposal two days later regarding a proposal which would see Concentra, which is controlled by Tang Capital Partners, acquire all outstanding shares of the company for $3.80 per share in cash. The offer also includes a contingent value right (CVR) representing the right to receive 80% of the net proceeds payable from licensing or offloading any of Theseus' programmes.Earlier this year, Concentra acquired Jounce Therapeutics in a deal that saw the latter pull out of a prior merger agreement with Redx Pharma. It also made a move to buy Atea Pharmaceuticals that was ultimately rejected. Last month, Concentra offered to buy all outstanding shares of Rain Oncology for $1.25 per share in cash, plus a CVR representing the right to receive 80% of the net proceeds payable from any license or disposition of Rain's programmes.